Modern poultry processing facilities use a conveyor system to transport the carcasses of domestic fowl, such as chicken or turkeys, from one work station to the next during processing operations. The typical overhead conveyor system in a poultry processing plant includes an endless conveyor chain mounted on an overhead track assembly and driven at a desired speed by one or more motors. A succession of shackles is attached to the overhead conveyor chain and the shackles hang downwardly from that chain. Each shackle is intended to receive an individual fowl in a head-down configuration, and each shackle typically defines a pair of open-ended loops which engage and hold the feet of the fowl for that purpose. Overhead conveyor systems of the kind described are known to those skilled in the art.
Although poultry processing has become highly mechanized through the development of specialized machinery to perform most repetitive operations on the carcasses of freshly-killed fowl, loading the live fowl onto the conveyor shackles at the beginning of the processing line has eluded any significant mechanization thus far. An operator must physically grab each fowl by its legs, turn the fowl upside-down so the legs are uppermost, and then insert each leg through one of the loops in a shackle as that shackle moves past the operator standing alongside the overhead conveyor. Because the shackles are spaced closely together in succession along the conveyor line, the efforts of several different people are required to make sure the fowl is loaded onto each shackle in order to obtain maximum efficiency of the processing equipment located downline from the loading zone. Loading the fowl onto the conveyor shackles thus is labor intensive, especially as compared with other processing operations (e.g., plucking and eviscerating) that are substantially or completely mechanized. Moreover, the job of loading live fowl, which may have been kept penned for many hours immediately preceding the loading operation, onto conveyor shackles is known as one of the dirtiest and most unpleasant jobs in a poultry processing plant.
The prior art is sparse with regard to apparatus for automating or mechanizing the process of loading live fowl onto the shackles of conveyor lines. Published European patent application 89201624.7 (EPO Publication No. 355,037) contains a schematic showing of apparatus which causes fowl to stand up on a conveyor belt so that the legs can be placed to engage the shackles, presumably by a human operator. U.S. Pat. Nos. 4,301,770 and 4,307,683 disclose apparatus for gathering the live fowl at the farm and there attaching shackles that are separate from the conveyor at the processing plant. The shackled fowl are transported from the farm to the processing plant, at which the shackled fowl are removed from pens and the shackles attached to the overhead conveyor. The impracticalities of that latter scheme include the need for twice handling the fowl during separate shackling and loading operations, and the need to return the shackles from the processing plant to the farms for reuse. It is believed that no commercially-practicable apparatus existed for loading birds onto shackles of a conveyor system, prior to the present invention.